Introduction to Clade
A clade is a group of organisms that includes an ancestor and all of its descendants. This biological classification system is based on evolutionary relationships, rather than strictly on physical characteristics.
Clade vs. Taxon
While clades and taxa both refer to groupings of organisms, the key difference is that a clade includes all descendants of a common ancestor, while a taxon may not. For example, a clade may include birds and dinosaurs, while a taxon like ‘reptiles’ may not include birds.
Types of Clades
- Monophyletic: Includes a common ancestor and all of its descendants
- Paraphyletic: Includes a common ancestor but not all of its descendants
- Polyphyletic: Includes multiple ancestors that do not share a common ancestor
Example of a Clade
The clade ‘primates’ includes humans, apes, monkeys, and their common ancestor. This group is defined by shared characteristics such as forward-facing eyes and grasping hands.
Case Study: Mammals
When studying mammals, scientists use clades to group specific species based on genetic similarities and evolutionary history. By analyzing these relationships, researchers can better understand the evolutionary pathways of mammals.
Statistics on Clades
According to a recent study, over 90% of plant species belong to a single clade known as angiosperms. This clade includes flowering plants that have dominated terrestrial ecosystems for millions of years.
